Image stabilizing optical lens device with decentering of lens sub-unit

ABSTRACT

An image stabilizing optical lens device including, in order from an object side to an image side of the image stabilizing optical lens device, a first lens unit having positive refractive power, a second lens unit having negative refractive power and being movable along an optical axis of the image stabilizing optical lens device to perform focusing, and a third lens unit having positive refractive power, the third lens unit including a front lens sub-unit having negative refractive power and being movable so as to be decentered with respect to the optical axis and a rear lens sub-unit having positive refractive power.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image stabilizing optical lensdevice for use in an image-taking optical system and having a so-calledanti-vibration function which stabilizes an image against vibration ofthe image-taking optical system. More particularly, the presentinvention relates to an optical system having an anti-vibration functionof inner focus type, which is capable of preventing degradation ofoptical performance which otherwise would be caused when theanti-vibration effect is produced by moving an anti-vibration movablelens unit in a direction which is, for example, perpendicular to theoptical axis.

2. Description of the Related Art

Image pickup by an image pickup device such as a camera on a runningvehicle such as a motorcar or an aircraft tends to suffer from blur ofthe image due to vibration transmitted from the vehicle to an imagepickup optical system, such as a photographing lens of the image pickupdevice.

It is difficult to stabilize the image against vibration of the imagepickup optical system, particularly when the image pickup optical systemhas a long focal length. More specifically, when the image pickupoptical system is tilted due to vibration, the picked-up image vibratesat an amplitude which corresponds to the product of the angle of tiltand the focal length of the image pickup optical system. Therefore, astill image pickup apparatus is required to employ an exposure timewhich is short enough to avoid degradation of the image quality whichotherwise would be caused due to vibration, whereas a dynamic imagepickup apparatus suffers a problem of difficulty in maintenance of theimage composition. In picking up images with these apparatuses,therefore, it is necessary to effect compensation for tilting of theimage pickup optical system caused by vibration, thereby preventingvibratory displacement of the picked-up image, i.e., blur of the image.

Anti-vibration optical systems having a function of preventing blur of apicked-up image are disclosed in, for example, Japanese Patent Laid-OpenNo. 50-80147, Japanese Patent Publication No. 56-21133 and JapanesePatent Laid-Open No. 61-223819.

More specifically, Japanese Patent Laid-Open No. 50-80147 discloses azoom lens device incorporating a pair of afocal variable power systemsincluding a first system having an angular magnification M₁ and a secondsystem having an angular magnification M₂. Magnifying or power varyingoperations are performed by the first and second focal variable powersystems in such a manner as to meet the condition of M₁=1−1/M₂, whilethe second variable power system is spatially fixed, thereby effectingcompensation for vibration of an image, and thus stabilizing thepicked-up image.

Japanese Patent Publication No. 56-21133 discloses a system in whichvibration of an optical system is detected by a detecting means, and apart of the optical components is moved in response to an output fromthe detecting means in a direction for canceling vibratory displacementof an image, thereby stabilizing the image.

Japanese Patent Laid-Open No. 61-223819 discloses an image pickupoptical system in which a refractive variable-apex-angle prism isdisposed closest to the object, the apex angle of the prism being variedto deflect the image in such a manner as to compensate for vibration ofthe image pickup optical system, thereby stabilizing the image.

In apparatuses of the type disclosed in Japanese Patent Publication Nos.56-34847, 57-7414 and so forth, an image pickup optical system isprovided in a portion thereof with an optical element which is spatiallyfixed against vibration of the image pickup optical system. The opticalelement produces a prism effect in accordance with the vibration of theoptical system so as to deflect the picked-up image, whereby a stillimage is obtained on the focal plane.

A method also has been proposed in which a lens unit in an image pickupoptical system is vibrated in the direction perpendicular to the opticalsystem in response to an output from an acceleration sensor which sensesvibration of the image pickup optical system, thereby stabilizing thepicked-up image. This method is proposed, for example, in thespecifications of U.S. Pat. Nos. 5,000,549 and 4,974,950, as well as inU.S. patent application Ser. No. 425,749 filed Apr. 2, 1995 now U.S.Pat. No. 5,598,299.

In general, image stabilizing devices of the type which produces astable still image by vibrating a lens unit so as to cancel the effectof vibration of the optical system are required to provide a largeamplitude of compensation for image vibration with a small amplitude oramount of vibratory movement or rotation of the lens unit, i.e., amovable lens unit having plural lenses, which is vibrated to cancel theeffect of vibration of the optical system.

Decentering of a movable lens unit causes a blur of the image due toeccentric aberration accompanying compensation for image vibration, whena large aberration occurs, such as eccentric comatic aberration,eccentric astigmatism, eccentric chromatic aberration or eccentric fieldcurvature aberration. For instance, occurrence of a large eccentricdistortion causes a large difference between the amount of movement ofthe image on the optical axis and the amount of movement of the image inthe peripheral region. Therefore, when the movable lens unit isdecentered in such a manner as to compensate for vibration of the imageon the optical axis, a phenomenon resembling the blur of the image takesplace in the peripheral region, so as to seriously impair the opticalcharacteristics.

Thus, an optical system having an anti-vibration function, incorporatinga movable lens unit movable perpendicularly to the optical axis with orwithout simultaneous slight rotation about a point on the optical axisso as to cause decentering, has to meet the following requirements.

The first requirement is that the amount of eccentricity aberrationcaused when the movable lens unit is moved perpendicularly to theoptical axis with or without simultaneous rotation, is small enough tosuppress degradation of the image quality attributable to suchaberration.

The second requirement is that the optical system has a largedecentering sensitivity, which is defined as the ratio Δx/ΔH of theamount Δx of correction of image vibration to the unit amount ΔH ofdecentering movement. This requirement is in order that a large effectof image vibration prevention is obtained with a small amount ofmovement or rotation of the movable lens unit, thus contributing to areduction in the size of the whole apparatus.

The optical system having an anti-vibration function relying on spatialfixing of an optical element cannot suitably be used in small andlight-weight apparatuses, because of difficulty encountered in thespatial fixing of the element and in the design of a small-sized opticalsystem.

The optical system which employs a variable-apex-angle prism disposedclosest to the object also is disadvantageous in that it requires alarge-size actuator and in that it is not easy to simply correcteccentric chromatic aberration, although it provides an advantage thatalmost no aberration other than eccentric (decentering) chromaticaberration is caused.

The optical system of the type which relies on decentering of a lensunit can have a reduced size, provided that the lens unit to bedecentered is suitably selected and positioned. This type of opticalsystem, however, suffers from a problem in that it is not easy toachieve a large amount of compensation against vibration with a smallamount of actuation while satisfactorily correcting aberrations causedby the decentering, such as eccentricity coma aberration, eccentricityastigmatism, eccentricity field curvature and so forth.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an optical systemhaving an anti-vibration function of the type in which a selected lensunit is moved in the direction perpendicular to the optical axis so asto compensate for image vibration, thereby stabilizing the image,wherein the lens elements of the lens unit are suitably arranged so asto enable satisfactory correction of various kinds of aberration, whilerealizing a large amount of compensation for image vibration with asmall amount of decentering, thus contributing to reduction in the sizeof the whole apparatus. Such an optical system is particularly suitablefor use as an inner-focus-type medium-telephoto optical system.

To this end, in one aspect, the present invention relates to an imagestabilizing optical lens device, comprising, in order from an objectside to an image side of the image stabilizing optical lens device, afirst lens unit having positive refractive power, a second lens unithaving negative refractive power and being movable along an optical axisof the image stabilizing optical lens device to perform focusing, and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to be decentered withrespect to the optical axis, and a rear lens sub-unit having positiverefractive power.

In this image stabilizing optical lens device, the focal distances ofthe lens units are determined in relation to the overall focal length ofthe whole image stabilizing optical lens device, in such a manner as tomeet the conditions of the following equations (1) to (3) in which fiindicates the focal length of the i-th lens unit, and f represents theoverall focal length of the whole image stabilizing optical lens device.

0.4<f1/f<0.8  (1)

0.4<f2/f<0.8  (2)

 0.4<f3/f<0.8  (3)

In another aspect, the present invention relates to an image stabilizingoptical apparatus comprising, in order from an object side to an imageside of the image stabilizing optical lens device, a first lens unithaving positive refractive power, a second lens unit having negativerefractive power and being movable along an optical axis of the imagestabilizing optical lens device to perform focusing, and a third lensunit having positive refractive power and including, in order from theobject side to the image side, a front lens sub-unit having negativerefractive power and being movable so as to be decentered with respectto the optical axis, and a rear lens sub-unit having positive refractivepower, wherein the front lens sub-unit is movable so as to be decenteredaway from the optical axis in one of (i) a direction perpendicular tothe optical axis of the image stabilizing optical apparatus and (ii) adirection along a spherical path defined by a point on the optical axisdisposed a predetermined distance towards the image side away from thethird lens unit.

The above and other objects, features and advantages of the presentinvention will become clear from the following description of thepreferred embodiments when the same is read in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic sectional view of a lens system in accordancewith a first numerical example of the present invention;

FIG. 2 is a diagrammatic sectional view of a lens system in accordancewith a second numerical example of the present invention;

FIG. 3 is a diagrammatic sectional view of a lens system in accordancewith a third numerical example of the present intention;

FIG. 4 is a diagrammatic sectional view of a lens system in accordancewith a fourth numerical example of the present invention;

FIGS. 5A(1), 5A(2), 5A(3), and 5A(4) are diagrams showing longitudinalaberration as observed when the object distance is 50 times as large thefocal length in the first numerical example;

FIGS. 5B(1), 5B(2), and 5B(3) are diagrams showing transverse aberrationin normal state as observed when the object distance is 50 times aslarge as the focal length in the first numerical example;

FIGS. 5C(1), 5C(2), and 5C(3) are diagrams showing transverse/aberrationas observed after a power correction at an image plane of 1° when theobject distance is 50 times as large as the focal length in the firstnumerical example;

FIGS. 6A(1), 6A(2), 6A(3), and 6A(4) are diagrams showing longitudinalaberration as observed when the object distance is 50 times as large asthe focal length in the second numerical example;

FIGS. 6B(1), 6B(2), and 6B(3) are diagrams showing transverse aberrationin normal state as observed when the object distance is 50 times aslarge as the focal length in the second numerical example;

FIGS. 6C(1), 6C(2), and 6C(3) are diagrams showing transverse aberrationas observed after a power correction at an image plane of 1° when theobject distance is 50 times as large as the focal length in the secondnumerical example;

FIGS. 7A(1), 7A(2), 7A(3), and 7A(4) are diagrams showing longitudinalaberration as observed when the object distance is 50 times as large asthe focal length in the third numerical example;

FIGS. 7B(1), 7B(2), and 7B(3) are diagrams showing transverse aberrationin normal state as observed when the object distance is 50 times aslarge as the focal length in the third numerical example;

FIG. 7C(1), 7C(2), 7C(3) are diagrams showing transverse aberration asobserved after a power correction at an image plane of 1° when theobject distance is 50 times as large as the focal length in the thirdnumerical example;

FIGS. 8A(1), 8A(2), 8A(3), and 8A(4) are diagrams showing longitudinalaberration as observed when the object distance is 50 times as large asthe focal length in the fourth numerical example;

FIGS. 8B(1), 8B(2), and 8B(3) are diagrams showing transverse aberrationin normal state as observed when the object distance is 50 times aslarge as the focal length in the fourth numerical example;

FIGS. 8C(1), 8C(2), and 8C(3) are diagrams showing transverse aberrationas observed after a power correction at an image plane of 1° when theobject distance is 50 times as large as the focal length in the fourthnumerical example;

FIG. 9 is a schematic diagrammatic illustration of a lens arrangementexplanatory of compensation for eccentric aberration effected in thepresent invention; and

FIGS. 10A and 10B are schematic diagrammatic illustrations of lensarrangements explanatory of compensation for eccentric aberrationeffected in the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 to 4, which are diagrammatic sectional views oflens systems in accordance with first to fourth numerical examples of anembodiment of the present invention, respectively, there are shown, inorder from an object side to an image plane side of the lens system, afirst lens unit L1 having a positive refractive power, a second lensunit L2 having a negative refractive power, and a third lens unit L3having a positive refractive power. The third lens unit L3 includes, inorder from the object side to the image plane side, a front lenssub-unit L3 a having a negative refractive power and a rear lenssub-unit L3 b having a positive refractive power. Change of focus frominfinity towards the closest point is effected by moving the second lensunit L2 towards the image plane as indicated by an arrow LF. The frontlens sub-unit L3 a is movable as indicated by an arrow LT in thedirection perpendicular to the optical axis A of the lens system so asto effect correction, i.e., vibration compensation, against any blur ofthe picked-up image, caused by vibration of the optical system. Theimage plane is indicated by IP. Thus, the illustrated examples performinner focusing and correction against blur of the image. At the sametime, optical constants of the lens units are determined in accordancewith the aforementioned conditional equations (1), (2) and (3). Thisenables effective correction against blur of the picked-up image, whileachieving reduction in the size of the whole optical system. At the sametime, the optical system of this embodiment effectively reducesgeneration of aberrations attributable to the movement of the front lenssub-unit L3 a in the direction perpendicular to the optical axis, i.e.,eccentricity aberrations attributable to the decentering such aseccentricity comma aberration, eccentricity astigmatism, eccentricityfield curvature and so forth, thus offering superior opticalperformance.

A description will now be given of the technical significance of theconditions represented by the equations (1) to (3). The conditionalequations (1), (2) and (3) determine the ranges of ratios of the focallengths of the first, second and the third lens units, respectively, tothe whole optical system. These conditions are intended tosatisfactorily suppress various types of aberration and to reduce thesize of the whole lens system, so as to enable the lens system to beused suitably as a medium-telephoto image pickup optical system, whilepreventing an excessive increase in the amount of movement of the secondlens unit which serves as the focusing lens unit.

Decrease of the focal length of the first lens unit to a value below thelower limit of the range specified by the conditional equation (1)increases difficulty encountered in achieving the correction againstaberrations, although it helps in reduction in the overall length of theoptical system. Conversely, increase of the focal length of the firstlens unit beyond the upper limit of the range specified by the equation(1) tends to increase the overall length of the optical system, althoughit facilitates correction against aberrations.

Reduction of the focal length of the second lens unit to a value belowthe lower limit of the range specified by the equation (2) on one handoffers an advantage in that the amount of movement of the second lensunit required for focusing can be decreased, but on the other handincreases difficulty in the correction against aberrations. Conversely,increase of the focal length of the second lens unit beyond the upperlimit of the range specified by the equation (2) undesirably increasesthe amount of movement of the second lens unit required for focusing,although it facilitates correction against aberrations.

Reduction of the focal length of the third lens unit below the lowerlimit of the range specified by the condition (3) makes it necessary toset the composite refractive power of the first and second lens units toa small positive value or a negative value, resulting in an increasedoverall length of the optical system. Conversely, when the focal lengthof the third lens unit is increased beyond the upper limit of the rangespecified by the equation (3), the symmetry of the whole optical systemis impaired so as to generate many asymmetrical aberrations which aredifficult to eliminate, although the overall length of the opticalsystem tends to become small.

The described embodiment of the optical system of the invention havingan anti-vibration function is designed such that the optical distancesof the respective lens units meet the conditions of the equations (1) to(3), respectively, so as to realize a medium-telephoto image pickupoptical system having an appropriate arrangement of refractive power. Inaddition, the third lens unit is composed of a front lens sub-unit L3 ahaving a negative refractive power and a rear lens sub-unit L3 b havinga positive refractive power, the front lens sub-unit L3 a being movablein the direction substantially perpendicular to the optical axis of theoptical system, so as to effect compensation for the influence ofvibration of the optical system.

By virtue of the above-described features of lens arrangement, thepresent invention effectively reduces eccentricity aberrations whileeffecting correction against blur of a picked-up image, thus attainingsuperior optical performance.

According to the present invention, in order to achieve furtherimprovement in optical performance by further reduction in theeccentricity aberrations caused by the anti-vibration correctingoperation, it is advisable that at least one of the following conditions(i) to (v) is met:

(i) Each of the front lens sub-unit L3 a and the rear lens sub-unit L3 bis composed of a lens group having at least one positive lens and atleast one negative lens. Such an arrangement of lenses can efficientlyeliminate eccentricity aberrations which are produced during vibrationcompensation.

In general, eccentricity aberrations generated during vibrationcompensation depend on the quantities of light rays impinging upon andemitted from each lens unit and the amount of residual aberration ineach lens unit. In order to effectively reduce the aberrations,therefore, it is necessary to appropriately set the arrangement ofrefractive power, as well as residual aberration, in each lens unit. Tocope with such requirements, in this embodiment, it is preferred thateach lens sub-unit is composed of a lens group which includes at leastone positive lens and at least one negative lens, and residualaberration of each lens sub-unit is suitably corrected.

In order to enable free setting of the Petzval sum of a lens unit havinga given refractive power and composed of a single element lens, it is aneffective measure to increase or decrease the refractive index of thelens by employing lens materials of different levels of refractivepower. However, when ordinary lens materials are to be used, it isdifficult to greatly vary the Petzval sum, because such ordinary lensmaterials can provide only a limited range of refractive power. In viewof this fact, in this embodiment, each lens unit is composed of a lensunit group having at least one positive lens and at least one negativelens, in order to allow a greater freedom of setting of residualaberration of each lens unit.

(ii) It is preferred that the condition of the following equation (4) issatisfied:

0.15<|f3 a/f|<0.5  (4)

where f3 a represents the focal length of the front lens sub-unit L3 a.

The equation (4) determines the range of the ratio, to the focal lengthof the whole optical system, of the focal length of the front lenssub-unit L3 a which constitutes the component of the third lens unit L3closer to the object and which is to be moved in the directionperpendicular to the optical axis when vibration compensation iseffected. This condition is intended to realize required vibrationcompensation performance with a reduced amount of movement of the frontlens sub-unit L3 a, while suppressing generation of eccentricityaberrations.

When the focal length of the front lens sub-unit L3 a is reduced belowthe lower limit of the range specified by the equation (4), it isdifficult to reduce the number of element lenses of the front lenssub-unit L3 a while appropriately setting the residual aberration,making it difficult to obtain a compact construction of the whole lenssystem.

Conversely, increase of the focal length of the front lens sub-unit L3 abeyond the upper limit of the range specified by the equation (4) makesit difficult to obtain a large value of the decentering sensitivitywhich is ratio of the amount of decentering of the lens unit to theamount of displacement of the picked-up image, so that a greater amountof driving of the front lens sub-unit L3 a is required for a certainamount of vibration compensation, although such an increase in the focallength is advantageous from the viewpoint of suppression of aberrations.

When the focal length of the front lens sub-unit L3 a is set so as tofall out of the range specified by the equation (4), it is difficult toeffect correction against eccentricity aberrations caused by decenteringof the front lens sub-unit L3 a, in an optical system which is designedto meet only the requirements of the equations (1) to (3).

(iii) It is preferred that the first lens unit has a pair of positivelenses and a negative lens, while the second lens unit has a positivelens and a negative lens. With this arrangement, it is possible toobtain an optical system which is better suited for use in amedium-telephoto image pickup system.

In the medium-telephoto type optical system of this embodiment, the lensunits have their own functions. Namely, the first lens unit has aprimary function of image formation. The second lens unit performs afocusing function, while contributing to the reduction in the overalllength of the optical system. The third lens unit includes a lenssub-unit having the vibration compensation function, and serves toachieve symmetry of arrangement of refractory power, so as to enableeffective correction against asymmetrical aberrations.

In order to perform these functions, each of the lens units ispreferably composed of a plurality of lenses. More specifically, thefirst lens unit, which has to have a positive refractive power toperform the image forming function, preferably has at least two positivelenses in order to perform a satisfactory image forming function overthe viewing angle of the medium-telephoto image pickup optical systemhaving a compact construction.

It is also preferred that the first lens unit incorporates a negativelens, in order to effectively perform satisfactory correction ofchromatic aberration.

The second lens unit is intended to perform a focusing function and toprovide a reduced overall length of the whole optical system and, hence,has a negative refractive power. In order to reduce variation inaberrations during focusing, in particular the variation in thechromatic aberration, it is preferred that the second lens unit has atleast one positive lens and at least one negative lens, so as tosatisfactorily reduce chromatic aberration.

Thus, the described embodiment employs appropriate lens arrangements forthe first and second lens units, thus achieving an optical system havingsuperior optical performance.

(iv) It is preferred that the condition of the following equation (5) ismet:

0.15<Da/f<0.5  (5)

where Da represents the distance between the apex of the lens surface ofthe first lens unit closest to the image plane and the apex of the lenssurface of the third lens unit closest to the object.

The equation (5) determines the ratio, to the overall focal length ofthe whole optical system of the distance between the first and thirdlens units which are kept stationary during focusing. This condition isintended to provide a space large enough to accommodate the movement ofthe second lens unit during focusing, without causing any excessiveincrease in the overall length of the optical system. Obviously, whenthe distance between the first lens unit and the third lens unit isreduced to a value below the lower limit of the range specified by theequation (5), the focusing movement of the second lens unit isundesirably limited, so that the closest focal point obtainable with theoptical system is not sufficiently close to the optical system.Conversely, when the distance between the first lens unit and the thirdlens unit exceeds the upper limit of the range specified by the equation(5), the overall length of the whole optical system is undesirablyincreased.

The optical system in accordance with the present invention, whendesigned and constructed to met the condition of the equation (5), issatisfactory both in the compactness of the construction and closenessof the closest focal point.

(v) From the viewpoint of aberration correction, the lens unitspreferably have the following constructions.

More specifically, it is preferred that the first lens unit has one ofthe following three types of arrangement (a) to (c):

(a) four lenses in total, including two positive lenses having convexsides directed to the object, and a positive lens and a negative lensadhered to each other;

(b) three lenses in total, including two positive lenses having convexsides directed to the object, and a negative lens both sides of whichare concave; and

(c) four lenses in total, including two positive lenses having convexsides directed to the object, a negative lens having both sides concave,and a meniscus-type positive lens having a convex side directed to theobject.

It is also preferred that the second lens unit is composed of ameniscus-type lens obtained by adhering a positive lens and a negativelens to each other, with the convex side directed to the object.

It is also preferred that the front lens sub-unit L3 a is constitutedeither by (a) a combination of (i) a composite lens obtained by adheringa positive lens having both sides convex and a negative lens having bothsides concave, and (ii) a negative lens having both sides concave, or by(b) a combination of a meniscus-type positive lens with the convex sidedirected to the image plane and a negative lens having both sidesconcave.

It is also preferred that the rear lens sub-unit L3 b is constituted bya combination of (i) a positive lens with both sides convex and (ii) acomposite lens obtained by adhering a positive lens having both sidesconvex and (ii) a negative lens to each other.

A description will now be given of the optical characteristics of theoptical system of the invention having an anti-vibration function.

In general, a translational decentering movement of a lens unit of anoptical system, intended to effect correction against blur of imagecaused by vibration, is inevitably accompanied by impairment of imageforming performance due to generation of eccentricity aberrations. Areference is therefore made to a method which was proposed by MATSUI inthe 23rd Conference of Applied Physics (1962). Based on the theory ofaberration, this method is aimed at eliminating eccentric aberrationswhich occur when a movable lens unit in an optical system having anarbitrary refractive power arrangement is moved in the directionperpendicular to the optical axis to prevent an image from becomingblurred.

As expressed by the following formula (a), the amount ΔY1 of aberrationof the whole optical system caused by a translational decentering of alens unit P of the optical system by an amount E is the sum of theamount ΔY of aberration before the decentering and the amount ΔY(E) ofaberration caused by the decentering. The amount ΔY is expressed in thefollowing formula (b) in terms of the spherical aberration (I), comaaberration (II), astigmatism (III), Petzval sum (P) and distortion (Y).The eccentricity aberration ΔY(E) is expressed, as given by thefollowing formula (c), in terms of the primary eccentricity comaaberration (IIE), primary eccentricity astigmatism (IIIE), primaryeccentric field curvature (PE), primary eccentricity distortion (VE1),primary eccentricity distortion additional aberration (VE2) and primaryorigin movement (ΔE).

From the formula (d), it is understood that, in an optical system inwhich a lens group P is translationally decentered, the aberrations (ΔE)to (VE2) of the formula (i) can be expressed by using aberrationcoefficients Ip, IIp, IIIp, Pp and Vp of the lens unit P and aberrationcoefficients Iq, IIq, IIIQ, Pq and Vq of an imaginary lens group q whichis constituted by all the lens units positioned between the lens unit Pand the image plane, with the angles of incidence of light to the lensunit P expressed by a and αa_(p). $\begin{matrix}{{\Delta \quad {Y1}} = {{\Delta \quad Y} + {\Delta \quad {Y(E)}}}} & \text{(a)} \\\begin{matrix}{{\Delta \quad Y} = \quad {- {\left( {{1/2}\quad \alpha_{k^{\prime}}} \right)\left\lbrack {{\left( {N_{1}\tan \quad \omega} \right)^{3}\quad \cos \quad \varphi \quad {\omega \cdot V}} +} \right.}}} \\{\quad {\left( {N_{1}\tan \quad \omega} \right)^{2}R\left\{ {{2\quad \cos \quad {\varphi\omega}\quad \cos \quad {\left( {\varphi_{R} - {\varphi\omega}} \right) \cdot {III}}} +} \right.}} \\{{\quad \left. {\cos \quad {\varphi_{R}\left( {{III} + P} \right)}} \right\}} + {\left( {N_{1}\tan \quad \omega} \right)R^{2}\left\{ {{2\quad \cos \quad \varphi_{R}\cos \quad \left( {\varphi_{R} - {\varphi \quad \omega}} \right)} +} \right.}} \\\left. {{{\quad \left. {\cos \quad \varphi \quad \omega} \right\}} \cdot {II}} + {R^{3}\cos \quad {\varphi \cdot I}}} \right\rbrack\end{matrix} & \text{(b)} \\\begin{matrix}{{\Delta \quad {Y(E)}} = \quad {- {\left( {{E/2}\alpha_{k^{\prime}}} \right)\left\lbrack {{\left( {N_{1}\tan \quad \omega} \right)^{2}\left\{ {{\left( {2 + {\cos \quad 2\varphi \quad \omega}} \right)({VE1})} - ({VE2})} \right\}} +} \right.}}} \\{\quad {2\left( {N_{1}\tan \quad \omega} \right){R\left\lbrack \left\{ {{\cos \quad \left( {\varphi_{R} - {\varphi\omega}} \right)} +} \right. \right.}}} \\{\left. {{{\quad \left. {\cos \quad \left( {\varphi_{R} + {\varphi\omega}} \right)} \right\}}\quad ({IIIE})} + {\cos \quad \varphi_{R}\quad \cos \quad \varphi \quad {\omega \cdot ({PE})}}} \right\rbrack +} \\{{\quad \left. {{R^{2}\left( {2 + {\cos^{2}\varphi_{R}}} \right)}({IIE})} \right\rbrack} - {\left( {{E/2}\quad \alpha_{k^{\prime}}} \right)\left( {\Delta \quad E} \right)}}\end{matrix} & \text{(c)} \\{\left( {\Delta \quad E} \right) = {{{- 2}\quad \left( {\alpha_{p}^{\prime} - \alpha_{p}} \right)} = {{- 2}h_{p}\varphi_{p}}}} & \text{(d)} \\\begin{matrix}{({IIE}) = \quad {{\alpha_{p^{\prime}}{II}_{q}} - {\alpha_{p}\left( {{II}_{p} + {II}_{q}} \right)} - {\alpha \quad a_{p}^{\prime}I_{q}} + {\alpha \quad {a_{p}\left( {I_{p} + I_{q}} \right)}}}} \\{= \quad {{h_{p}\varphi_{p}{II}_{q}} - {\alpha_{p}{II}_{p}} - \left( {{{ha}_{p}\varphi_{p}I_{q}} - {\alpha \quad a_{p}I_{p}}} \right)}}\end{matrix} & \text{(e)} \\\begin{matrix}{({IIIE}) = \quad {{\alpha_{p}^{\prime}{III}_{q}} - {\alpha_{p}\left( {{III}_{p} + {III}_{q}} \right)} - {\alpha \quad a_{p}^{\quad \prime}{II}_{q}} + {\alpha \quad {a_{p}\left( {{II}_{p} + {II}_{q}} \right)}}}} \\{= \quad {{h_{p}\varphi_{p}{III}_{q}} - {\alpha_{p}{III}_{p}} - \left( {{{ha}_{p}\varphi_{p}{II}_{q}} - {\alpha \quad a_{p}{II}_{p}}} \right)}}\end{matrix} & \text{(f)} \\{({PE}) = {{{\alpha_{p}^{\prime}P_{q}} - {\alpha_{p}\left( {P_{p} + P_{q}} \right)}} = {{h_{p}\varphi_{p}P_{q}} - {\alpha_{p}P_{p}}}}} & \text{(g)} \\\begin{matrix}{({VE1}) = \quad {{\alpha_{p}^{\prime}V_{q}} - {\alpha_{p}\left( {V_{p} + V_{q}} \right)} - {\alpha \quad a_{p}^{\prime}{III}_{q}} + {\alpha \quad {a_{p}\left( {{III}_{p} + {III}_{q}} \right)}}}} \\{= \quad {{h_{p}\varphi_{p}V_{q}} - {\alpha_{p}V_{p}} - \left( {{h\quad a_{p}\varphi_{p}{III}_{q}} - {\alpha \quad a_{p}{III}_{p}}} \right)}}\end{matrix} & \text{(h)} \\{({VE2}) = {{{\alpha \quad a_{p}P_{q}} - {\alpha \quad {a_{p}\left( {P_{p} + P_{q}} \right)}}} = {{h\quad a_{p}\varphi_{p}P_{q}} - {\alpha \quad a_{p}P_{p}}}}} & \text{(i)}\end{matrix}$

From these formulae, it is understood that suppression of eccentricityaberrations requires that the aberration coefficients I_(p), II_(p),III_(p), P_(p) And V_(p) of the lens unit P are set t small values orthat the lenses are arranged in good balance such that the coefficientsare canceled by each other as shown by the formulae (a) to (i).

A description will now be given of the optical operation of the opticalsystem of the invention having the anti-vibration function, withreference to a model of an anti-vibration optical system of the type ofthe type shown in FIG. 9, in which a lens unit is decentered in thedirection perpendicular to the optical axis so as to compensate fordisplacement of the picked-up image.

In order to realize a sufficiently large amount of compensation forimage displacement with a sufficiently small amount of decentering, itis necessary that the amount (ΔE) of the primary origin movement is setto a sufficiently large value. Conditions for compensating for theprimary eccentricity field curvature (PE) will be considered based onthis knowledge.

The optical system shown in FIG. 9 has three lens units: a lens unit oclosest to the object, an intermediate lens unit p and a lens unit gclosest to the image plane, among which the lens unit p istranslationally movable in the direction perpendicular to the opticalaxis so as to effect vibration compensation thereby eliminating blur ofthe image.

For application in the formulae shown above, the values of therefractive power of the lens units o, p and g are respectivelyrepresented by Φ_(o), (Φ_(p) and (Φ_(q). Angles of incidence of theparaxial light ray and extra-axial light ray are respectivelyrepresented by a and αa, while the heights of incidence of these lightrays are respectively represented by h and ha. Suffixes o, p and qindicative of the lens groups are attached to these factors α, αa, h andha, as well as to aberration coefficients. It is assumed that each lensunit is composed of few lenses and that the aberration coefficientsexhibit tendencies of insufficiency of correction.

A discussion will now be given-on Petzval sums of the lens units.Petzval sums Po, Pp and Pq of the lens units are proportional to thevalues Φ_(o), Φ_(p) and Φ_(q) of refractive power of the respective lensunits. More specifically, the following conditions are roughly met:

Po=CΦ_(o)

Pp=CΦ_(p)

Pq=CΦ_(q)

where C represents a constant

Substituting the conditions shown above, the primary eccentricity fieldcurvature (PE) generated as a result of the translational decentering ofthe lens unit p can be transformed as follows:

(PE)=CΦ_(p)(h_(p)Φ_(q)−α_(p))

Therefore, in order to effect a correction against the eccentricityfield curvature (PE), it is necessary that either a condition Φ_(p)=0 ora condition Φ_(q)=α_(p)/h_(p) is met. If the first condition, i.e.,Φ_(p)=0, is adopted, compensation for image displacement cannot beperformed, because the primary origin movement (ΔE) is zero under such acondition. It is therefore necessary to determine the solution whichsatisfies the other condition: namely, Φ_(q)=α_(p)/h_(p). This meansthat α_(p) and Φ_(q) are of the same sign, e.g., plus or minus, sinceh_(p) is greater than 0 (plus).

a) When αp is greater than 0 (α_(p)>0):

In order to effect correction against eccentricity field curvature,Φ_(q) should be greater than 0 (Φ_(q)>0) and (Φ_(o)>0 is essentiallymet. In this case, if the condition of Φ_(p)>0 is also satisfied, α_(p)and α′_(p) satisfy the condition of 0<α_(p)<α′_(p)<1, and the primaryorigin point movement (ΔE) is expressed by

(ΔE)=−2(α′_(p)−α_(p))>−2

Thus, the decentering sensitivity, which is the ratio of the amount ofdisplacement of the picked-up image to the unit amount of displacementof the decentering lens unit, takes a value which is smaller than 1. Inaddition, as stated before, the decentering sensitivity is zero when thecondition of Φ_(p)=0 is met. In this case, therefore, Φ_(p) must bedetermined to meet the condition of Φ_(p)<0.

b) When a is smaller than 0 (α_(p)<0):

In order to effect correction against eccentricity field curvature (PE),Φ_(q) should be smaller than 0 (Φ_(q)<0) and Φ_(o)<0 is essentially met.In this case, therefore, the condition of Φ_(p)>0 is essentially met.

From the foregoing discussion, it is understood that refractive powerarrangements a and b as shown in the following Table 1 are suitably usedin the optical system, in order that the optical system can effectcorrection against the primary eccentricity field curvature, whileobtaining a sufficiently large value of the primary origin pointmovement (ΔE).

TABLE 1 Lens unit o p q Refractive power a Positive Negative Positive bNegative Positive Negative

These refractive power arrangements are illustrated in FIGS. 10A and10B.

The present invention is based on these refractive power arrangements. Adescription will now be given as to the features of the lens arrangementin accordance with the present invention. In general, an optical systemis designed in such a way as to enable effective corrections againstvarious types of aberrations with a compact lens arrangement, bysuitably determining the refractive power of the lens units. When theoptical system is designed such that a selected lens unit of the opticalsystem is translationally decentered in the direction perpendicular tothe optical axis so as to compensate for the displacement of picked-upimage, it is advisable that the lens unit to be decentered is selectedso as to attain a sufficiently large decentering sensitivity, as well asease of correction against eccentricity aberrations.

Meanwhile, in order to achieve a compact construction of the opticalsystem and, hence, of the apparatus employing such an optical system, itis desirable that a lens unit having comparatively small outsidedimensions is selected as the lens unit to be decentered.

From these points of view, the optical system which achieves the presentinvention adopts the refractive power arrangement which is shown in FIG.10A.

Thus, the optical system in accordance with the present invention has afirst lens unit which is closest to the object and which has positiverefractive power, an intermediate second lens unit which has negativerefractive power, and a third lens unit which is most remote from theobject and which has positive refractive power. The second lens unit ismovable along the optical axis to perform focusing, while the first andthe third lens units are kept stationary. The third lens unit includes(a) a front lens sub-unit closer to the object and having negativerefractive power and (b) a rear lens sub-unit more remote from theobject and having positive refractive power, the front lens sub-unitbeing movable in the direction perpendicular to the optical axis so asto compensate for vibration of the picked-up image caused by vibrationof the optical system, thereby preventing the image from blurring.

In the illustrated embodiment of the invention, the second lens unit isused for focal adjustment so that the normalized tilt angles of theparaxial light impinging upon the front lens sub-unit and the paraxiallight emitted from the front lens sub-unit are maintained to besubstantially constant, thereby minimizing variation in the eccentricityaberrations caused by the focusing operation.

Numerical examples of the embodiment of the present invention are shownbelow, in which: Ri represents the radius of curvature of the i-th lenssurface as counted from the end adjacent to the object, Di representsthe i-th lens thickness and spatial distance as counted from the endadjacent to the object, and Ni and vi respectively represent therefractive index and Abbe number of the i-th lens as counted from theend adjacent to the object. The values of the aforesaid conditionalequations, as calculated based on the numerical values of the respectivenumerical examples, are shown in Table 2.

Representing the values such as the focal length by mm (millimeter), thefirst and second numerical examples are based on an assumption that thefront lens sub-unit is movable substantially in the vertical directionalong an imaginary spherical surface centered at a point on the opticalaxis about 400 mm apart rearward, i.e., towards the image plane, fromthe third lens unit.

The third numerical example is based on an assumption that the frontlens sub-unit is moved along an imaginary spherical surface centered atinfinity, i.e., that the front lens sub-unit is decenteredtranslationally. In the fourth numerical example, the front lenssub-unit is assumed to move along an imaginary spherical surfacecentered at a point on the optical axis about 200 mm apart rearward,i.e., towards the image plane, from the third lens unit.

<Numerical Example 1> f = 133.82  Fno = 1:2.9  2ω = 18.37° R1 = 78.98 D1= 6.0 N1 = 1.51633 ν1 = 64.2 R2 = 7666.28 D2 = 0.2 R3 = 68.62 D3 = 5.5N2 = 1.51633 ν2 = 64.2 R4 = 606.30 D4 = 0.2 R5 = 61.94 D5 = 8.0 N3 =1.51633 ν3 = 64.2 R6 = −420.18 D6 = 2.0 N4 = 1.80518 ν4 = 25.4 R7 =81.18 D7 = 20.0 R8 = 307.55 D8 = 3.0 N5 = 1.80518 ν5 = 25.4 R9 = −114.08D9 = 1.5 N6 = 1.77250 ν6 = 49.6 R10 = 49.90 D10 = 13.0 R11 = 272.59 D11= 3.0 N7 = 1.76182 ν7 = 26.5 R12 = −40.50 D12 = 1.3 N8 = 1.51742 ν8 =52.4 R13 = 64.23 D13 = 1.5 R14 = −119.76 D14 = 1.3 N9 = 1.77250 ν9 =49.6 R15 = 46.25 D15 = 4.0 R16 = 99.04 D16 = 3.0 N10 = 1.77250 ν10 =49.6 R17 = −126.36 D17 = 0.2 R18 = 59.37 D18 = 5.0 N11 = 1.77250 ν11 =49.6 R19 = −42.57 D19 = 1.3 N12 = 1.80518 ν12 = 25.4 R20 = 736.42 Backfocus 50.680 <Numerical Example 2> f = 134.33  Fno = 1:2.9  2ω = 18.30°R1 = 72.34 D1 = 7.0 N1 = 1.51633 ν1 = 64.2 R2 = −2378.61 D2 = 0.2 R3 =61.33 D3 = 6.0 N2 = 1.51633 ν2 = 64.2 R4 = 345.87 D4 = 0.2 R5 = 62.48 D5= 7.0 N3 = 1.51633 ν3 = 64.2 R6 = −381.13 D6 = 2.0 N4 = 1.80518 ν4 =25.4 R7 = 78.31 D7 = 20.0 R8 = 358.77 D8 = 3.0 N5 = 1.80518 ν5 = 25.4 R9= −55.17 D9 = 1.3 N6 = 1.77250 ν6 = 49.6 R10 = 43.22 D10 = 13.0 R11 =−72.44 D11 = 2.5 N7 = 1.76182 ν7 = 26.5 R12 = −41.42 D12 = 2.0 R13 =−55.26 D13 = 1.2 N8 = 1.77250 ν8 = 49.6 R14 = 47.27 D14 = 5.0 R15 =104.24 D15 = 3.0 N9 = 1.77250 ν9 = 49.6 R16 = −115.90 D16 = 0.2 R17 =59.56 D17 = 5.0 N10 = 1.77250 ν10 = 49.6 R18 = −61.25 D18 = 1.4 N11 =1.80518 ν11 = 25.4 R19 = 817.71 Back focus 50.153 <Numerical Example 3>f = 134.40  Fno = 1:2.9  2ω = 18.29° R1 = 73.37 D1 = 7.5 N1 = 1.51633 ν1= 64.2 R2 = −222.89 D2 = 0.2 R3 = 61.87 D3 = 6.0 N2 = 1.51633 ν2 = 64.2R4 = 909.30 D4 = 1.5 R5 = −315.45 D5 = 2.0 N3 = 1.80518 ν3 = 25.4 R6 =91.94 D6 = 0.2 R7 = 61.86 D7 = 4.5 N4 = 1.51633 ν4 = 64.2 R8 = 354.65 D8= 20.0 R9 = 236.29 D9 = 3.0 N5 = 1.80518 ν5 = 25.4 R10 = −72.50 D10 =1.5 N6 = 1.77250 ν6 = 49.6 R11 = 43.00 D11 = 13.0 R12 = 235.58 D12 = 3.5N7 = 1.76182 ν7 = 26.5 R13 = −36.42 D13 = 1.3 N8 = 1.51742 ν8 = 52.4 R14= 68.66 D14 = 1.5 R15 = −91.17 D15 = 1.3 N9 = 1.77250 ν9 = 49.6 R16 =46.32 D16 = 3.0 R17 = 124.54 D17 = 3.0 N10 = 1.77250 ν10 = 49.6 R18 =−105.77 D18 = 0.2 R19 = 53.64 D19 = 5.5 N11 = 1.77250 ν11 = 49.6 R20 =−33.65 D20 = 1.3 N12 = 1.80518 ν12 = 25.4 R21 = 500.80 Back focus 50.299<Numerical Example 4> f = 134.45  Fno = 1:2.9  2ω = 18.28° R1 = 62.44 D1= 7.0 N1 = 1.60311 ν1 = 60.7 R2 = −481.91 D2 = 0.2 R3 = 53.62 D3 = 6.5N2 = 1.60311 ν2 = 60.7 R4 = −630.77 D4 = 1.5 R5 = −274.49 D5 = 2.0 N3 =1.80518 ν3 = 25.4 R6 = 85.53 D6 = 20.0 R7 = 80.43 D7 = 3.0 N4 = 1.60342ν4 = 38.0 R8 = 289.23 D8 = 1.5 N5 = 1.77250 ν5 = 49.6 R9 = 36.78 D9 =13.0 R10 = 68.99 D10 = 3.5 N6 = 1.76182 ν6 = 26.5 R11 = −42.67 D11 = 1.3N7 = 1.60311 ν7 = 60.7 R12 = 29.10 D12 = 3.0 R13 = −53.18 D13 = 1.3 N8 =1.77250 ν8 = 49.6 R14 = 220.20 D14 = 3.0 R15 = 91.48 D15 = 3.5 N9 =1.77250 ν9 = 49.6 R16 = −89.23 D16 = 0.2 R17 = 57.57 D17 = 6.0 N10 =1.60311 ν10 = 60.7 R18 = −34.49 D18 = 1.5 N11 = 1.80518 ν11 = 25.4 R19 =−182.92 Back focus 50.345

TABLE 2 Numerical Examples Conditions 1 2 3 4 (1) f1/f 0.61 0.57 0.570.60 (2) |f2/f| 0.60 0.50 0.53 0.60 (3) f3/f 1.38 1.11 1.49 1.41 (4)|f3a/f| 0.34 0.34 0.33 0.32 (5) Da/f 0.28 0.28 0.28 0.28

As will be understood from the foregoing description, according to thepresent invention, there is provided an image stabilizing optical deviceof the type in which a selected lens unit of the optical system isdriven and decentered in the direction perpendicular to the optical axisso as to effect correction against displacement of a picked-up image,thereby eliminating blur of the image, wherein the lens elements areappropriately arranged so as to enable effective correction againstvarious kinds of eccentricity aberrations and so as to achieve a largeamount of correction against displacement of the picked-up image with asufficiently small amount of decentering driving. According to thepresent invention, it is thus possible to obtain an optical lens devicehaving an anti-vibration function for stabilizing an image, which issuitable for use as an inner-focus-type medium-telephoto image pickupoptical system.

What is claimed is:
 1. An image stabilizing optical lens devicecomprising, in order from an object side to an image side of said imagestabilizing optical lens device: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical lens device to perform focusing, wherein said second lens unitmoves toward the image side during change of focus from infinity towardsa closest point, said second lens unit consisting of a positive lens anda negative lens; and a third lens unit having positive refractive powerand including, in order from the object side to the image side, a frontlens sub-unit having negative refractive power and a rear lens sub-unithaving positive refractive power, wherein of said front lens sub-unitand said rear lens sub-unit, only said front lens sub-unit is movable soas to be decentered with respect to the optical axis, and wherein saidfirst lens unit and said third lens unit are fixed in the optical axisdirection.
 2. An image stabilizing optical lens device according toclaim 1, wherein each of said front lens sub-unit and said rear lenssub-unit comprises at least one lens having positive refractive powerand at least one lens having negative refractive power.
 3. An imagestabilizing optical lens device according to claim 1, wherein said firstlens unit comprises a pair of lenses each having positive refractivepower and a lens having negative refractive power, and said second lensunit comprises a lens having positive refractive power and a lens havingnegative refractive power.
 4. An image stabilizing optical lens deviceaccording to claim 1, wherein said first lens unit comprises twopositive lenses having convex sides directed to the object side, and apositive lens and a negative lens adhered to each other.
 5. An imagestabilizing optical lens device according to claim 1, wherein said firstlens unit comprises two positive lenses having convex sides directed tothe object, and a negative lens both sides of which are concave.
 6. Animage stabilizing optical lens device according to claim 1, wherein saidsecond lens unit comprises a meniscus-type lens including a positivelens and a negative lens adhered to each other, with a convex side ofsaid meniscus-type lens being directed to the object side.
 7. An imagestabilizing optical lens device according to claim 1, wherein said frontlens sub-unit comprises (i) a composite lens obtained by adhering apositive lens having both sides convex and a negative lens having bothsides concave, and (ii) a negative lens having both sides concave.
 8. Animage stabilizing optical lens device according to claim 1, wherein saidfront lens sub-unit comprises (i) a meniscus-type positive lens with aconvex side of said meniscus-type positive lens being directed to theimage side and (ii) a negative lens having both sides concave.
 9. Animage stabilizing optical lens device according to claim 1, wherein saidrear lens sub-unit comprises (i) a positive lens with both sides convexand (ii) a composite lens comprising a positive lens having both sidesconvex and a negative lens adhered to each other.
 10. An imagestabilizing optical lens device according to claim 1, wherein said firstlens unit consists of two positive lenses having convex sides directedto the object side, and a positive lens and a negative lens adhered toeach other.
 11. An image stabilizing optical lens device comprising, inorder from an object side to an image side of said image stabilizingoptical lens device: a first lens unit having positive refractive power;a second lens unit having negative refractive power and being movablealong an optical axis of said image stabilizing optical lens device toperform focusing; and a third lens unit having positive refractive powerand including, in order from the object side to the image side, a frontlens sub-unit having negative refractive power and a rear lens sub-unithaving positive refractive power, wherein of said front lens sub-unitand said rear lens sub-unit, only said front lens sub-unit is movable soas to be decentered with respect to the optical axis, wherein said firstlens unit and said third lens unit are fixed in the optical axisdirection, and wherein when f3 a is a focal length of said front lenssub-unit and f is an overall focal length of said image stabilizingoptical lens device as a whole, the following condition is satisfied:0.15<|f3 a/f|<0.5.
 12. An image stabilizing optical lens devicecomprising, in order from an object side to an image side of said imagestabilizing optical lens device: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein when Da is a distancebetween an apex of the lens surface of said first lens unit closest tothe object side and an apex of a lens surface of said third lens unitclosest to the object side, and f is an overall focal length of saidimage stabilizing optical lens device as a whole, the followingcondition is satisfied: 0.15<Da/f<0.5.
 13. An image stabilizing opticallens device comprising, in order from an object side to an image side ofsaid image stabilizing optical lens device: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein when f is an overallfocal length of said image stabilizing optical lens device as a whole,and f3 is a focal length of said third lens unit, the followingcondition is satisfied: 0.8<f3/f<5.0.
 14. An image stabilizing opticallens device comprising, in order from an object side to an image side ofsaid image stabilizing optical lens device: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein when f is an overallfocal length of said image stabilizing optical lens device as a whole,and f2 is a focal length of said second lens unit, the followingcondition is satisfied: 0.4<|f2/f|<0.8.
 15. An image stabilizing opticallens device comprising, in order from an object side to an image side ofsaid image stabilizing optical lens device: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein when f is an overallfocal length of said image stabilizing optical lens device as a whole,and f1 is a focal length of said first lens unit, the followingcondition is satisfied: 0.4<f1/f<0.8.
 16. An image stabilizing opticallens device comprising, in order from an object side to an image side ofsaid image stabilizing optical lens device: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein when f is an overallfocal length of said image stabilizing optical lens device as a whole,and f1 is a focal length of said first lens unit, and f2 is a focallength of said second lens unit, and f3 is a focal length of said thirdlens unit, the following conditions are satisfied: 0.4<f2/f|<0.8,0.4<f1/f<0.8, and 0.8<f3/f<5.0.
 17. An image stabilizing optical lensdevice comprising, in order from an object side to an image side of saidimage stabilizing optical lens device: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein said first lens unitcomprises two positive lenses having convex sides directed to the objectside, a negative lens having both sides concave, and a meniscus-typepositive lens having a convex side directed to the object side.
 18. Animage stabilizing optical apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing, whereinsaid second lens unit moves toward the image side during change of focusfrom infinity towards a closest point, said second lens unit consistingof a positive lens and a negative lens; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and being movable so as to become decentered with respect to theoptical axis and a rear lens sub-unit having positive refractive power,wherein of said front lens sub-unit and said rear lens sub-unit, onlysaid front lens sub-unit is movable so as to be decentered away from theoptical axis in one of (i) a direction perpendicular to the optical axisof said image stabilizing optical apparatus and (ii) a direction along aspherical path defined by a point on the optical axis disposed apredetermined distance towards the image side away from said third lensunit, and wherein said first lens unit and said third lens unit arefixed in the optical axis direction.
 19. An image stabilizing opticalapparatus according to claim 18, wherein said front lens sub-unit ismovable in a direction perpendicular to the optical axis of said imagestabilizing optical apparatus.
 20. An image stabilizing opticalapparatus according to claim 18, wherein said front lens sub-unit ismovable in a direction along the spherical path.
 21. An imagestabilizing optical apparatus according to claim 18, wherein said firstlens unit comprises two positive lenses having convex sides directed tothe object side, and a positive lens and a negative lens adhered to eachother.
 22. An image stabilizing optical apparatus according to claim 18,wherein said first lens unit comprises two positive lenses having convexsides directed to the object, and a negative lens both sides of whichare concave.
 23. An image stabilizing optical apparatus according toclaim 18, wherein said second lens unit comprises a meniscus-type lensincluding a positive lens and a negative lens adhered to each other,with a convex side of said meniscus-type lens being directed to theobject side.
 24. An image stabilizing optical apparatus according toclaim 18, wherein said front lens sub-unit comprises (i) a compositelens obtained by adhering a positive lens having both sides convex and anegative lens having both sides concave, and (ii) a negative lens havingboth sides concave.
 25. An image stabilizing optical apparatus accordingto claim 18, wherein said front lens sub-unit comprises (i) ameniscus-type positive lens with a convex side of said meniscus-typepositive lens being directed to the image side and (ii) a negative lenshaving both sides concave.
 26. An image stabilizing optical apparatusaccording to claim 18, wherein said rear lens sub-unit comprises (i) apositive lens with both sides convex and (ii) a composite lenscomprising a positive lens having both sides convex and a negative lensadhered to each other.
 27. An image stabilizing optical lens apparatusaccording to claim 18, wherein said first lens unit consists of twopositive lenses having convex sides directed to the object side, and apositive lens and a negative lens adhered to each other.
 28. An imagestabilizing optical apparatus comprising, in order from an object sideto an image side of said image stabilizing optical apparatus: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein when f3 a is a focal length of said front lens sub-unit, and fis an overall focal length of said image stabilizing optical apparatusas a whole, the following condition is satisfied: 0.15<|f3 a/f|<0.5. 29.An image stabilizing optical apparatus comprising, in order from anobject side to an image side of said image stabilizing opticalapparatus: a first lens unit having positive refractive power; a secondlens unit having negative refractive power and being movable along anoptical axis of said image stabilizing optical apparatus to performfocusing; and a third lens unit having positive refractive power andincluding, in order from the object side to the image side, a front lenssub-unit having negative refractive power and being movable so as tobecome decentered with respect to the optical axis and a rear lenssub-unit having positive refractive power, wherein of said front lenssub-unit and said rear lens sub-unit, only said front lens sub-unit ismovable so as to be decentered away from the optical axis in one of (i)a direction perpendicular to the optical axis of said image stabilizingoptical apparatus and (ii) a direction along a spherical path defined bya point on the optical axis disposed a predetermined distance towardsthe image side away from said third lens unit, wherein said first lensunit and said third lens unit are fixed in the optical axis direction,and wherein when Da is a distance between an apex of a lens surface ofsaid first lens unit closest to the object side and an apex of a lenssurface of said third lens unit closest to the object side, and f is anoverall focal length of said image stabilizing optical apparatus as awhole, the following condition is satisfied: 0.15<Da/f<0.5.
 30. An imagestabilizing optical apparatus comprising, in order from an object sideto an image side of said image stabilizing optical apparatus: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein when f is an overall focal length of said image stabilizingoptical apparatus as a whole, and f3 is a focal length of said thirdlens unit, the following condition is satisfied: 0.8<f3/f<5.0.
 31. Animage stabilizing optical apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein when f is an overall focal length of said image stabilizingoptical apparatus as a whole, and f1 is a focal length of said firstlens unit, and f2 is a focal length of said second lens unit, and f3 isa focal length of said third lens unit, the following conditions aresatisfied: 0.4<|f2/f|<0.8, 0.4<f1/f<0.8, and 0.8<f3/f<5.0.
 32. An imagestabilizing optical apparatus comprising, in order from an object sideto an image side of said image stabilizing optical apparatus: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein f is an overall focal length of said image stabilizing opticalapparatus as a whole, and f2 is a focal length of said second lens unit,the following condition is satisfied: 0.4<|f2/f|<0.8.
 33. An imagestabilizing optical apparatus comprising, in order from an object sideto an image side of said image stabilizing optical apparatus: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein when f is an overall focal length of said image stabilizingoptical apparatus as a whole, and f1 is a focal length of said firstlens unit, the following condition is satisfied: 0.4<f1/f<0.8.
 34. Animage stabilizing optical apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein said first lens unit comprises two positive lenses having convexsides directed to the object side, a negative lens having both sidesconcave, and a meniscus-type positive lens having a convex side directedto the object side.
 35. An image stabilizing optical lens devicecomprising, in order from an object side to an image side of said imagestabilizing optical lens device: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein said first lens unitconsists of two positive lenses having convex sides directed to theobject, and a negative lens both sides of which are concave.
 36. Animage stabilizing optical lens device comprising, in order from anobject side to an image side of said image stabilizing optical lensdevice: a first lens unit having positive refractive power; a secondlens unit having negative refractive power and being movable along anoptical axis of said image stabilizing optical lens device to performfocusing; and a third lens unit having positive refractive power andincluding, in order from the object side to the image side, a front lenssub-unit having negative refractive power and a rear lens sub-unithaving positive refractive power, wherein of said front lens sub-unitand said rear lens sub-unit, only said front lens sub-unit is movable soas to be decentered with respect to the optical axis, wherein said firstlens unit and said third lens unit are fixed in the optical axisdirection, and wherein said first lens unit consists of two positivelenses having convex sides directed to the object side, a negative lenshaving both sides concave, and a meniscus-type positive lens having aconvex side directed to the object side.
 37. An image stabilizingoptical lens device comprising, in order from an object side to an imageside of said image stabilizing optical lens device: a first lens unithaving positive refractive power; a second lens unit having negativerefractive power and being movable along an optical axis of said imagestabilizing optical lens device to perform focusing; and a third lensunit having positive refractive power and including, in order from theobject side to the image side, a front lens sub-unit having negativerefractive power and a rear lens sub-unit having positive refractivepower, wherein of said front lens sub-unit and said rear lens sub-unit,only said front lens sub-unit is movable so as to be decentered withrespect to the optical axis, wherein said first lens unit and said thirdlens unit are fixed in the optical axis direction, and wherein saidsecond lens unit consists of a meniscus-type lens including a positivelens and a negative lens adhered to each other, with a convex side ofsaid meniscus-type lens being directed to the object side.
 38. An imagestabilizing optical lens device comprising, in order from an object sideto an image side of said image stabilizing optical lens device: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical lens device to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and a rear lens sub-unit having positiverefractive power, wherein of said front lens sub-unit and said rear lenssub-unit, only said front lens sub-unit is movable so as to bedecentered with respect to the optical axis, wherein said first lensunit and said third lens unit are fixed in the optical axis direction,and wherein said front lens sub-unit consists of (i) a composite lensobtained by adhering a positive lens having both sides convex and anegative lens having both sides concave, and (ii) a negative lens havingboth sides concave.
 39. An image stabilizing optical lens devicecomprising, in order from an object side to an image side of said imagestabilizing optical lens device: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical lens device to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and a rear lens sub-unit having positive refractive power, whereinof said front lens sub-unit and said rear lens sub-unit, only said frontlens sub-unit is movable so as to be decentered with respect to theoptical axis, wherein said first lens unit and said third lens unit arefixed in the optical axis direction, and wherein said front lenssub-unit consists of (i) a meniscus-type positive lens with a convexside of said meniscus-type positive lens being directed to the imageside and (ii) a negative lens having both sides concave.
 40. An imagestabilizing optical lens device comprising, in order from an object sideto an image side of said image stabilizing optical lens device: a firstlens unit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical lens device to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and a rear lens sub-unit having positiverefractive power, wherein of said front lens sub-unit and said rear lenssub-unit, only said front lens sub-unit is movable so as to bedecentered with respect to the optical axis, wherein said first lensunit and said third lens unit are fixed in the optical axis direction,and wherein said rear lens sub-unit consists of (i) a positive lens withboth sides convex and (ii) a composite lens consisting of a positivelens having both sides convex and a negative lens adhered to each other.41. An image stabilizing optical lens device comprising, in order froman object side to an image side of said image stabilizing optical lensdevice: a first lens unit having positive refractive power; a secondlens unit having negative refractive power and being movable along anoptical axis of said image stabilizing optical lens device to performfocusing; and a third lens unit having positive refractive power andincluding, in order from the object side to the image side, a front lenssub-unit having negative refractive power and being movable so as to bedecentered with respect to the optical axis, and a rear lens sub-unithaving positive refractive power, wherein when f is an overall focallength of said image stabilizing optical lens device as a whole, and f3is a focal length of said third lens unit, the following condition issatisfied: 0.8<f3/f<5.0.
 42. An image stabilizing optical lens deviceaccording to claim 41, wherein when f1 is a focal length of said firstlens unit, and f2 is a focal length of said second lens unit, thefollowing conditions are satisfied: 0.4<|f2/f|<0.8, 0.4<f1/f<0.8, and0.8<f3/f<5.0.
 43. An image stabilizing optical lens device comprising,in order from an object side to an image side of said image stabilizingoptical lens device: a first lens unit having positive refractive power;a second lens unit having negative refractive power and being movablealong an optical axis of said image stabilizing optical lens device toperform focusing; and a third lens unit having positive refractive powerand including, in order from the object side to the image side, a frontlens sub-unit having negative refractive power and being movable so asto be decentered with respect to the optical axis, and a rear lenssub-unit having positive refractive power, wherein when f is an overallfocal length of said image stabilizing optical lens device as a whole,and f2 is a focal length of said second lens unit, the followingcondition is satisfied: 0.4<|f2/f|<0.8.
 44. An image stabilizing opticalapparatus comprising, in order from an object side to an image side ofsaid image stabilizing optical apparatus: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical apparatus to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and being movable so as to become decentered with respect to theoptical axis and a rear lens sub-unit having positive refractive power,wherein said front lens sub-unit is movable so as to be decentered awayfrom the optical axis in one of (i) a direction perpendicular to theoptical axis of said image stabilizing optical apparatus and (ii) adirection along a spherical path defined by a point on the optical axisdisposed a predetermined distance towards the image side away from saidthird lens unit, and wherein when f is an overall focal length of saidimage stabilizing optical apparatus as a whole, and f3 is a focal lengthof said third lens unit, the following condition is satisfied:0.8<f3/f<5.0.
 45. An image stabilizing optical apparatus according toclaim 44, wherein when f1 is a focal length of said first lens unit, andf2 is a focal length of said second lens unit, the following conditionsare satisfied: 0.4<|f2/f|<0.8, 0.4<f1/f<0.8, and 0.8<f3/f<5.0.
 46. Animage stabilizing optical apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein said front lens sub-unit is movableso as to be decentered away from the optical axis in one of (i) adirection perpendicular to the optical axis of said image stabilizingoptical apparatus and (ii) a direction along a spherical path defined bya point on the optical axis disposed a predetermined distance towardsthe image side away from said third lens unit, and wherein when f is anoverall focal length of said image stabilizing optical apparatus as awhole, and f2 is a focal length of said second lens unit, the followingcondition is satisfied: 0.4<|f2/f|<0.8.
 47. An image stabilizing opticallens device comprising, in order from an object side to an image side ofsaid image stabilizing optical lens device: a first lens unit havingpositive refractive power; a second lens unit having negative refractivepower and being movable along an optical axis of said image stabilizingoptical lens device to perform focusing, wherein said second lens unitmoves toward the image side during change of focus from infinity towardsa closest point, said second lens unit consisting of a positive lens anda negative lens; and a third lens unit having positive refractive powerand including a decentering lens sub-unit and another lens sub-unit,wherein of said decentering lens sub-unit and said another lenssub-unit, only said decentering lens sub-unit is movable so as to bedecentered with respect to the optical axis, and wherein said first lensunit and said third lens unit are fixed in the optical axis direction.48. An image stabilizing optical lens device according to claim 47,wherein said decentering lens sub-unit has negative refractive power,and said another lens sub-unit has positive refractive power.
 49. Animage stabilizing optical lens device comprising, in order from anobject side to an image side of said image stabilizing optical lensdevice: a first lens unit having positive refractive power; a secondlens unit having negative refractive power and being movable along anoptical axis of said image stabilizing optical lens device to performfocusing; and a third lens unit having positive refractive power andincluding a decentering lens sub-unit and another lens sub-unit, whereinof said decentering lens sub-unit and said another lens sub-unit, onlysaid decentering lens sub-unit is movable so as to be decentered withrespect to the optical axis, wherein said first lens unit and said thirdlens unit are fixed in the optical axis direction, and wherein when f isan overall focal length of said image stabilizing optical lens device asa whole, and f3 a is a focal length of said decentering lens sub-unit,the following condition is satisfied: 0.15<|f3 a/f|<0.5.
 50. An imagestabilizing optical lens apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein said first lens unit consists of two positive lenses havingconvex sides directed to the object, and a negative lens both sides ofwhich are concave.
 51. An image stabilizing optical lens apparatuscomprising, in order from an object side to an image side of said imagestabilizing optical apparatus: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical apparatus to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and being movable so as to become decentered with respect to theoptical axis and a rear lens sub-unit having positive refractive power,wherein of said front lens sub-unit and said rear lens sub-unit, onlysaid front lens sub-unit is movable so as to be decentered away from theoptical axis in one of (i) a direction perpendicular to the optical axisof said image stabilizing optical apparatus and (ii) a direction along aspherical path defined by a point on the optical axis disposed apredetermined distance towards the image side away from said third lensunit, wherein said first lens unit and said third lens unit are fixed inthe optical axis direction, and wherein said first lens unit consists oftwo positive lenses having convex sides directed to the object side, anegative lens having both sides concave, and a meniscus-type positivelens having a convex side directed to the object side.
 52. An imagestabilizing optical lens apparatus comprising, in order from an objectside to an image side of said image stabilizing optical apparatus: afirst lens unit having positive refractive power; a second lens unithaving negative refractive power and being movable along an optical axisof said image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein said second lens unit consists of a meniscus-type lens includinga positive lens and a negative lens adhered to each other, with a convexside of said meniscus-type lens being directed to the object side. 53.An image stabilizing optical lens apparatus comprising, in order from anobject side to an image side of said image stabilizing opticalapparatus: a first lens unit having positive refractive power; a secondlens unit having negative refractive power and being movable along anoptical axis of said image stabilizing optical apparatus to performfocusing; and a third lens unit having positive refractive power andincluding, in order from the object side to the image side, a front lenssub-unit having negative refractive power and being movable so as tobecome decentered with respect to the optical axis and a rear lenssub-unit having positive refractive power, wherein of said front lenssub-unit and said rear lens sub-unit, only said front lens sub-unit ismovable so as to be decentered away from the optical axis in one of (i)a direction perpendicular to the optical axis of said image stabilizingoptical apparatus and (ii) a direction along a spherical path defined bya point on the optical axis disposed a predetermined distance towardsthe image side away from said third lens unit, wherein said first lensunit and said third lens unit are fixed in the optical axis direction,and wherein said front lens sub-unit consists of (i) a composite lensobtained by adhering a positive lens having both sides convex and anegative lens having both sides concave, and (ii) a negative lens havingboth sides concave.
 54. An image stabilizing optical lens apparatuscomprising, in order from an object side to an image side of said imagestabilizing optical apparatus: a first lens unit having positiverefractive power; a second lens unit having negative refractive powerand being movable along an optical axis of said image stabilizingoptical apparatus to perform focusing; and a third lens unit havingpositive refractive power and including, in order from the object sideto the image side, a front lens sub-unit having negative refractivepower and being movable so as to become decentered with respect to theoptical axis and a rear lens sub-unit having positive refractive power,wherein of said front lens sub-unit and said rear lens sub-unit, onlysaid front lens sub-unit is movable so as to be decentered away from theoptical axis in one of (i) a direction perpendicular to the optical axisof said image stabilizing optical apparatus and (ii) a direction along aspherical path defined by a point on the optical axis disposed apredetermined distance towards the image side away from said third lensunit, wherein said first lens unit and said third lens unit are fixed inthe optical axis direction, and wherein said front lens sub-unitconsists of (i) a meniscus-type positive lens with a convex side of saidmeniscus-type positive lens being directed to the image side and (ii) anegative lens having both sides concave.
 55. An image stabilizingoptical lens apparatus comprising, in order from an object side to animage side of said image stabilizing optical apparatus: a first lensunit having positive refractive power; a second lens unit havingnegative refractive power and being movable along an optical axis ofsaid image stabilizing optical apparatus to perform focusing; and athird lens unit having positive refractive power and including, in orderfrom the object side to the image side, a front lens sub-unit havingnegative refractive power and being movable so as to become decenteredwith respect to the optical axis and a rear lens sub-unit havingpositive refractive power, wherein of said front lens sub-unit and saidrear lens sub-unit, only said front lens sub-unit is movable so as to bedecentered away from the optical axis in one of (i) a directionperpendicular to the optical axis of said image stabilizing opticalapparatus and (ii) a direction along a spherical path defined by a pointon the optical axis disposed a predetermined distance towards the imageside away from said third lens unit, wherein said first lens unit andsaid third lens unit are fixed in the optical axis direction, andwherein said rear lens sub-unit consists of (i) a positive lens withboth sides convex and (ii) a composite lens consisting of a positivelens having both sides convex and a negative lens adhered to each other.